Mitt Romney's campaign is out with a statement thanking Tim Pawlenty for his work for the campaign, as he steps down to become CEO of the Financial Services Roundtable (as Alex noted earlier), a job that doesn't permit partisan political activity:

Speaking to CNN's Soledad O'Brien, Tim Pawlenty said the negative back-and-forth between the campaigns -- which intensified yesterday on both sides — isn't "doing either side or the country as well as it could."